252299 2023-02-14 22:49:33 -0800 [Wasm-GC] Uninitialized locals with GC types are not initialized to jsNull() 2023-02-16 11:57:19 -0800 1 1 1 Unclassified WebKit WebAssembly WebKit Local Build Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 247394 1 tjc webkit-unassigned webkit-bug-importer oldest_to_newest 1933727 0 tjc 2023-02-14 22:49:33 -0800 The following test: ``` //@ runWebAssemblySuite("--useWebAssemblyTypedFunctionReferences=true", "--useWebAssemblyGC=true") import * as assert from "../assert.js"; import { compile, instantiate } from "./wast-wrapper.js"; function module(bytes, valid = true) { let buffer = new ArrayBuffer(bytes.length); let view = new Uint8Array(buffer); for (let i = 0; i < bytes.length; ++i) { print(bytes.charCodeAt(i)); view[i] = bytes.charCodeAt(i); } return new WebAssembly.Module(buffer); } function arrayGetUninitializedLocal() { let m = instantiate(`(module (type $a (array (mut i32))) (type $s (struct (field $x (mut i32)) (field $y (mut i64)))) (func (export "arrayGetNull") (local (ref null $a)) (drop (array.get $a (local.get 0) (i32.const 0))) ))`); assert.throws(() => m.exports.arrayGetNull(), WebAssembly.RuntimeError, "array.get to a null reference"); } arrayGetUninitializedLocal(); ``` causes a segfault. This is because of the `LLIntGenerator::addLocal()` method, which only initializes funcref-typed and extern-ref typed locals to the JS null value; not those with struct or array types. It should handle all ref types in the same way. 1933733 1 tjc 2023-02-14 23:06:54 -0800 Pull request: https://github.com/WebKit/WebKit/pull/10133 1934250 2 ews-feeder 2023-02-16 11:56:45 -0800 Committed 260389@main (7ce4006e3d05): <https://commits.webkit.org/260389@main> Reviewed commits have been landed. Closing PR #10133 and removing active labels. 1934251 3 webkit-bug-importer 2023-02-16 11:57:19 -0800 <rdar://problem/105558525>